This application, Interventions to decrease HIV infectiousness in Uganda, responds to the NIH Director's Opportunity for Research (RC-4) within the Global Health theme. Novel, cost-effective strategies are needed to efficiently deliver proven HIV prevention and treatment services in Africa to have a substantial impact on population HIV incidence. We posit that HIV transmission in a community can be reduced through targeted, population-level delivery of HIV prevention and care services to HIV+ persons, through increasing knowledge of HIV+ status with associated behavior change and reducing HIV infectiousness through initiation of antiretroviral therapy (ART), and prevention and treatment of co-infections such as malaria. Home-based HIV counseling and testing programs, HBCT, have achieved large scale knowledge of HIV serostatus. We will build on the HBCT platform (HBCT-plus) with targeted diagnostic, preventive, and treatment services for HIV+ persons and behavioral counseling to reduce HIV infectiousness, which will augment our Methods of Prevention Program Project (MP-3) research in Uganda. We will implement HBCT-plus in 5000 households in a high HIV prevalence area in Uganda with point-of-care (POC) CD4 testing to triage HIV+ persons to ART following Uganda guidelines and prevention and treatment of co-infections for all HIV+ persons. We will deliver prevention-for-positives risk-reduction counseling and discordant couples counseling to reduce risk behaviors. We will conduct quarterly follow-up visits for one year to optimize uptake of clinical interventions and to assess risk behaviors and stigma. Measures of success of HBCT-plus will be impact on: 1) community viral load (average HIV plasma viral load in the community over 12 months), a marker of population-level HIV infectiousness, and 2) HIV transmission potential, a composite measure of viral load and sexual behavior among HIV+ persons with HIV- or unknown serostatus partners, who have the greatest impact on HIV spread. Specific Aims: 1) Demonstrate feasibility of HBCT-plus, with HIV testing, POC CD4 testing to triage HIV+ persons to care, and prevention-for-positives and discordant couples counseling, delivered to 5000 households in Uganda in one year, based on >90% uptake of testing and >80% linkage to care among HIV+ persons. 2) Measure the impact of HBCT-plus on HIV transmission risk in the community through assessment of community viral load and HIV transmission potential before and after HBCT- plus. 3) Measure disclosure to partners and family, HIV testing of partners, condom use, sexual frequency, and number of partners before and after positive prevention counseling for newly-identified HIV+ persons through HBCT-plus. 4) Evaluate the effect of HBCT-plus on community risk behaviors, attitudes about HIV testing, and stigma through a probability sample survey in the community. 5) Determine the incremental costs of HBCT and additional components in HBCT-plus for facilitated HIV care and counseling, and estimate the cost-benefit of community viral load reduction. PUBLIC HEALTH RELEVANCE: HBCT-plus is a home-based HIV testing program in Uganda to increase knowledge of HIV+ status with associated behavior change, and reduce HIV infectiousness through effective linkages to antiretroviral therapy and treatment of co-infections, and assessed by reduction in community viral load and transmission potential.